A small cell node (SCN, Small Cell Node) is a low-power wireless access node and works on a licensed or unlicensed spectrum. A macro base station may cover several kilometers, and the small cell node may cover an area from 10 meters to 200 meters. The SCN may be applied to indoor and outdoor environments to expand a coverage area and increase a network capacity in combination with the macro base station (eNB, E-UTRAN NodeB). In a network deployment scenario shown in FIG. 1, a coverage area of an eNB is a coverage area illustrated by a dashed line 101, and a coverage area of an SCN is a coverage area illustrated by a solid line 102. Each of the eNB and the SCN may control one or more cells, a cell controlled by the eNB may be referred to as a macro cell, and a cell controlled by the SCN may be referred to as a small cell. In a sparse deployment scenario, a quantity of small cells is relatively small, and one or a few SCNs may be deployed in a service hotspot area. In a dense deployment scenario, a quantity of small cells is relatively large, and a large quantity of SCNs may be deployed in a service hotspot area. The SCN may assist the eNB in offloading a service of a heavily loaded eNB.
A Radio Resource Control Protocol (RRC, Radio Resource Control) message is layer 3 information for processing a control plane between user equipment (UE, User Equipment) and a base station. The RRC message is mainly responsible for allocating a radio resource and carrying all parameters needed during establishment, modification, and releasing of a layer 2 protocol entity and a physical layer protocol entity. Therefore, when establishing a connection to the base station, reestablishing a connection to the base station, and releasing a connection to the base station, the UE needs to interact with the base station by using the RRC message.
Although an SCN and an eNB may be enabled to cooperate to perform network deployment, in the prior art, the following special case still exists: In a movement process of UE, cell handovers are frequently performed between multiple macro cells, or between small cells, or between a macro cell and a small cell. Consequently, when the UE is handed over to a new cell in the movement process, the UE cannot reliably receive an RRC message such as a handover command due to inter-cell interference. Therefore, the UE cannot access the new cell in time, and even a handover failure is caused, which affects handover performance.